A. Field of the Invention
This invention relates to a noise reduction processing device for video signals.
B. Description of Related Art
The invention is especially applicable to the use of image intensifiers for increasing the sensitivity of a television camera, which cause a noisy picture. The noise is in the form of a speckle pattern of bright white dots above the background picture, which greatly detracts from the visual quality of the intensified picture. The noise specks are typically very short duration (one frame) single point (about one pixel) events.
Typically to remove this noise, integration techniques are used. Many frames of the output are averaged until the noise peaks are significantly reduced compared to the signal level. However, such integration causes so-called motion smear i.e. blurring, in the case of movement of the camera or of the scene's contents.